package cn.changeforyou.web.cloud.gateway.filter;

import cn.changeforyou.base.exception.JsonException;
import cn.changeforyou.base.model.Module;
import cn.changeforyou.web.cloud.gateway.utils.WebFluxUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.WebProperties;
import org.springframework.boot.autoconfigure.web.reactive.error.DefaultErrorWebExceptionHandler;
import org.springframework.boot.web.error.ErrorAttributeOptions;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.context.ApplicationContext;
import org.springframework.http.HttpStatus;
import org.springframework.web.reactive.function.server.*;

import java.util.HashMap;
import java.util.Map;

public class JsonExceptionHandler extends DefaultErrorWebExceptionHandler {

    private static Logger logger = LoggerFactory.getLogger(JsonExceptionHandler.class);

    public JsonExceptionHandler(ErrorAttributes errorAttributes, WebProperties.Resources resources,
                                ErrorProperties errorProperties, ApplicationContext applicationContext) {
        super(errorAttributes, resources, errorProperties, applicationContext);
    }

    /**
     * 获取异常属性
     */
    @Override
    protected Map<String, Object> getErrorAttributes(ServerRequest request, ErrorAttributeOptions options) {
        int code = HttpStatus.INTERNAL_SERVER_ERROR.value();
        Throwable error = super.getError(request);
        if (error instanceof org.springframework.cloud.gateway.support.NotFoundException) {
            code = HttpStatus.NOT_FOUND.value();
        }
        if (error instanceof JsonException) {
            JsonException jsonException = (JsonException) error;
            return WebFluxUtils.buildErrorMap(jsonException.getCode(), jsonException.getMessage());
        }
        return response(code, this.buildMessage(request, error));
    }

    /**
     * 指定响应处理方法为JSON处理的方法
     *
     * @param errorAttributes
     */
    @Override
    protected RouterFunction<ServerResponse> getRoutingFunction(ErrorAttributes errorAttributes) {
        return RouterFunctions.route(RequestPredicates.all(), this::renderErrorResponse);
    }


    /**
     * 根据code获取对应的HttpStatus
     *
     * @param errorAttributes
     * @return
     */
    @Override
    protected int getHttpStatus(Map<String, Object> errorAttributes) {
        int code = (int) errorAttributes.get("code");
        Module module = Module.getModuleByErrorCode(code);
        switch (module) {
            case AUTH_SERVICE:
                return HttpStatus.UNAUTHORIZED.value();
            case DATA_MODULE:
            case SYSTEM_MODULE:
            default:
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
        }
    }

    /**
     * 构建异常信息
     *
     * @param request
     * @param ex
     * @return
     */
    private String buildMessage(ServerRequest request, Throwable ex) {
        StringBuilder message = new StringBuilder("Failed to handle request [");
        message.append(request.methodName());
        message.append(" ");
        message.append(request.uri());
        message.append("]");
        if (ex != null) {
            message.append(": ");
            message.append(ex.getMessage());
        }
        return message.toString();
    }

    /**
     * 构建返回的JSON数据格式
     *
     * @param status       状态码
     * @param errorMessage 异常信息
     * @return
     */
    public static Map<String, Object> response(int status, String errorMessage) {
        Map<String, Object> map = new HashMap<>(3);
        map.put("code", status);
        map.put("message", errorMessage);
        map.put("data", null);
//        logger.error(map.toString());
        return map;
    }
}
